Diesel engine warm-up control system

Abstract

Upon the closing of the ignition circuit, this Diesel engine warm-up control system operates to establish a glow plug energizing circuit; to energize a "wait" indicator lamp and to produce a timed glow plug energization cycle signal. Upon the termination of this signal, the glow plug energizing circuit is maintained; the "wait" indicator lamp is deenergized and a "crank" indicator lamp is energized. The timed glow plug energization cycle signal is re-initiated upon engine crank to maintain the glow plugs energized for a controlled period of time after engine "start". A re-cycle feature which re-cycles the system in the event the engine does not start after crank, an automatic shutdown feature which deenergizes the glow plugs at the conclusion of the controlled period of time after the ignition circuit is closed in the event the engine is not cranked and a fast idle feature which provides engine fast idle during and for a predetermined time period after each cranking period at all engine temperatures are provided.

What is claimed is: 
     
       1. A Diesel enging warm-up control system for use with Diesel engines having at least one engine glow plug comprising in combination with a source of system operating potential: first circuit means for effecting the completion of a glow plug energizing circuit; means including a source of regulated direct current potential for producing an electrical engine temperature indicating signal of a potential magnitude inversely related to engine temperature; means for producing an electrical glow time timing signal which changes in potential magnitude with time at a rate determined by operating potential magnitude; second circuit means responsive to said engine temperature indicating and glow time timing signals for producing a timed glow plug energization cycle output signal while said engine temperature indicating signal is of a potential magnitude greater than said glow time timing signal whereby the duration of each glow plug energization cycle is a function of engine temperature and system operating potential magnitude; means for producing a crank signal while said engine is being cranked; means responsive to said crank signal for resetting said glow time timing signal to substantially zero thereby enabling said second circuit means to effect the production of another timed glow plug energization cycle output signal; means for producing an engine running signal while said engine is in the running mode subsequent to being cranked; and means included in said first circuit means for disabling said first circuit means and thereby effecting the interruption of said glow plug energizing circuit in response to the presence of said engine running signal and the termination of the said timed glow plug energization cycle signal produced by said second circuit means after said glow time timing signal was reset to substantially zero in response to said crank signal. 
     
     
       2. A Diesel engine warm-up control system for use with Diesel engines having at least one engine glow plug comprising in combination with a source of system operating potential and an electrically energizable "crank engine" indicating device: first circuit means for effecting the completion of a glow plug energizing circuit; means including a source of regulated direct current potential for producing an electrical engine temperature indicating signal of a potential magnitude inversely related to engine temperature; means for producing an electrical glow time timing signal which changes in potential magnitude with time at a rate determined by operating potential magnitude; second circuit means responsive to said engine temperature indicating and glow time timing signals for producing a timed glow plug energization cycle output signal while said engine temperature indicating signal is of a potential magnitude greater than said glow time timing signal whereby the duration of each glow plug energization cycle is a function of engine temperature and system operating potential magnitude; means responsive to the termination of said timed glow plug energization cycle signal for effecting the completion of an energizing circuit for said "crank engine" indicating device; means for producing a crank signal while said engine is being cranked; means responsive to said crank signal for resetting said glow time timing signal to substantially zero thereby enabling said second circuit means to effect the production of another timed glow plug energization cycle output signal; means for producing an engine running signal while said engine is in the running mode subsequent to being cranked; and means included in said first circuit means for disabling said first circuit means and thereby effecting the interruption of said glow plug energizing circuit in response to the presence of said engine running signal and the termination of the said timed glow plug energization cycle signal produced by said second circuit means after said glow time timing signal was reset to substantially zero in response to said crank signal. 
     
     
       3. A Diesel engine warm-up control system for use with Diesel engines having at least one engine glow plug comprising in combination with a source of system operating potential and an electrically energizable "crank engine" indicating device: first circuit means including at least a logic gate combination for effecting the completion of a glow plug energizing circuit; means including a source of regulated direct current potential for producing an electrical engine temperature indicating signal of a potential magnitude inversely related to engine temperature; means for producing an electrical glow time timing signal which changes in potential magnitude with time at a rate determined by operating potential magnitude; second circuit means responsive to said engine temperature indicating and glow time timing signals for producing a timed glow plug energization cycle output signal while said engine temperature indicating signal is of a potential magnitude greater than said glow time timing signal whereby the duration of each glow plug energization cycle is a function of engine temperature and system operating potential magnitude; means responsive to the termination of said timed glow plug energization cycle signal for effecting the completion of an energizing circuit for said "crank engine" indicating device; means for producing a crank signal while said engine is being cranked; means responsive to said crank signal for resetting said glow time timing signal to substantially zero thereby enabling said second circuit means to effect the production of another timed glow plug energization cycle output signal; means for producing an engine running signal while said engine is in the running mode subsequent to being cranked; and means for applying said engine running signal and said timed glow plug energization cycle signal to said logic gate combination of said first circuit means for disabling said first circuit means and thereby effecting the interruption of said glow plug energizing circuit in response to the presence of said engine running signal and the termination of the said timed glow plug energization cycle signal produced by said second circuit means after said glow time timing signal was reset to substantially zero in response to said crank signal. 
     
     
       4. A Diesel engine warm-up control system for use with Diesel engines having at least one engine glow plug comprising in combination with a source of system operating potential and an electrically energizable "crank engine" indicating device: first circuit means including at least a first logic gate combination for effecting the completion of a glow plug energizing circuit; means including a source of regulated direct current potential for producing an electrical engine temperature indicating signal of a potential magnitude inversely related to engine temperature; means for producing an electrical glow time timing signal which changes in potential magnitude with time at a rate determined by operating potential magnitude; second circuit means including at least a voltage comparator circuit responsive to said engine temperature indicating and glow time timing signals for producing a timed glow plug energization cycle output signal while said engine temperature indicating signal is of a potential magnitude greater than said glow time timing signal whereby the duration of each glow plug energization cycle is a function of engine temperature and system operating potential magnitude; means including a second logic gate combination and an electrically operable switching device responsive to the termination of said timed glow plug energization cycle signal for effecting the completion of an energizing circuit for said "crank engine" indicating device; means for producing a crank signal while said engine is being cranked; means responsive to said crank signals for resetting said glow time timing signal to substantially zero thereby enabling said second circuit means to effect the production of another timed glow plug energization cycle output signal; means for producing an engine running signal while said engine is in the running mode subsequent to being cranked; and means for applying said engine running signal and said timed glow plug energization cycle signal to said first logic gate combination of said first circuit means for disabling said first circuit means and thereby effecting the interruption of said glow plug energizing circuit in response to the presence of said engine running signal and the termination of the said timed glow plug energization cycle signal produced by said second circuit means after said glow time timing signal was reset to substantially zero in response to said crank signal. 
     
     
       5. A Diesel engine warm-up control system for use with Diesel engines having at least one engine glow plug comprising in combination with a source of system operating potential, a source of regulated potential, first and second constant current sources and an electrically energizable "crank engine" indicating device: first circuit means including at least a first logic gate combination for effecting the completion of a glow plug energizing circuit; means including a negative temperature coefficient thermistor device mounted upon said engine and energized by said source of regulated potential through a selected one of said constant current sources for producing an electrical engine temperature indicating signal of a potential magnitude inversely related to engine temperature; a glow time timing signal capacitor energized by said source of system operating potential through the other one of said constant current sources for producing an electrical glow time timing signal which changes in potential magnitude with time at a rate determined by operating potential magnitude; second circuit means including at least a voltage comparator circuit responsive to said engine temperature indicating and glow time timing signals for producing a timed glow plug energization cycle output signal while said engine temperature indicating signal is of a potential magnitude greater than said glow time timing signal whereby the duration of each glow plug energization cycle is a function of engine temperature and system operating potential magnitude; means including a second logic gate combination and an electrically operable switching device responsive to the termination of said timed glow plug energization cycle signal for effecting the completion of an energizing circuit for said "crank engine" indicating device; means for producing a crank signal while said engine is being cranked; means including a first voltage comparator circuit and a transistor controlled thereby responsive to said crank signal for discharging said glow time timing signal capacitor to substantially zero potential thereby enabling said second circuit means to effect the production of another timed glow plug energization cycle output signal; means including a second voltage comparator circuit for producing an engine running signal while said engine is in the running mode subsequent to being cranked; and means for applying said engine running signal and said timed glow plug energization cycle signal to said logic rate combination of said first circuit means for disabling said first circuit means and thereby effecting the interruption of said glow plug energizing circuit in response to the presence of said engine running signal and the termination of the said timed glow plug energization cycle signal produced by said second circuit means after said glow time timing signal was reset to substantially zero in response to said crank signal. 
     
     
       6. A Diesel engine warm-up control system for use with Diesel engines having at least one engine glow plug comprising in combination with a source of system operating potential and an electrically energizable "crank engine" indicating device: first circuit means including at least a first logic gate combination for effecting the completion of a glow plug energizing circuit; means including a sorce of regulated direct current potential for producing an electrical engine temperature indicating signal of a potential magnitude inversely related to engine temperature; means for producing a glow time electrical timing signal which changes in potential magnitude with time at a rate determined by operating potential magnitude; second circuit means responsive to said engine temperature indicating and glow time timing signals for producing a timed glow plug energization cycle output signal while said engine temperature indicating signal is of a potential magnitude greater than said glow time timing signal whereby the duration of each glow plug energization cycle is a function of engine temperature and system operating potential magnitude; means responsive to the termination of said timed glow plug energization cycle signal for effecting the completion of an energizing circuit for said "crank engine" indicating device; means for producing a crank signal while said engine is being cranked; means responsive to said crank signal for resetting said glow time timing signal to substantially zero thereby enabling said second circuit means to effect the production of another timed glow plug energization cycle output signal; means for producing a recycle signal a predetermined period of time after said engine has been cranked and has not started; and means for applying said recycle signal to said logic gate combination of said first circuit means for enabling said first circuit means to complete said glow plug energizing circuit. 
     
     
       7. A Diesel engine warm-up control system for use with Diesel engines having at least one engine glow plug comprising in combination with a source of system operating potential and an electrically energizable "crank engine" indicating device: first circuit means for effecting the completion of a glow plug energizing circuit; means including a source of regulated direct current potential for producing an electrical engine temperature indicating signal of a potential magnitude inversely related to engine temperature; means for producing a glow time electrical timing signal which changes in potential magnitude with time at a rate determined by operating potential magnitude; second circuit means responsive to said engine temperature indicating and glow time timing signals for producing a timed glow plug energization cycle output signal while said engine temperature indicating signal is of a potential magnitude greater than said glow time timing signal whereby the duration of each glow plug energization cycle is a function of engine temperature and system operating potential magnitude; means responsive to the termination of said timed glow plug energization cycle signal for effecting the completion of an energizing circuit for said "crank engine" indicating device; means responsive to said glow time timing signal for producing a system shut-down signal in the event said engine has not been cranked at the conclusion of a predetermined period of time; and means included in said first circuit means and responsive to said shut-down signal for disabling said first circuit means and thereby effecting the interruption of said glow plug energizing circuit. 
     
     
       8. A Diesel engine warm-up control system for use with Diesel engines having at least one engine glow plug comprising in combination with a source of system operating potential and an electrically energizable "crank engine" indicating device: first circuit means for effecting the completion of a glow plug energizing circuit; means including a source of regulated direct current potential for producing an electrical engine temperature indicating signal of a potential magnitude inversely related to engine temperature; means for producing a glow time electrical timing signal which changes in potential magnitude with time at a rate determined by operating potential magnitude; second circuit means responsive to said engine temperature indicating and glow time timing signals for producing a timed glow plug energization cycle output signal while said engine temperature indicating signal is of a potential magnitude greater than said glow time timing signal whereby the duration of each glow plug energization cycle is a function of engine temperature and system operating potential magnitude; means responsive to the termination of said timed glow plug energization cycle signal for effecting the completion of an energizing circuit for said "crank engine" indicating device; means for producing a crank signal while said engine is being cranked; means responsive to said crank signal for resetting said glow time timing signal to substantially zero thereby enabling said second circuit means to effect the production of another timed glow plug energization cycle output signal; means for producing an engine running signal while said engine is in the running mode subsequent to being cranked; means included in said first circuit means for disabling said first circuit means and thereby effecting the interruption of said glow plug energizing circuit in response to the presence of said engine running signal and the termination of the said timed glow plug energization cycle signal produced by said second circuit means after said glow time timing signal was reset to substantially zero in response to said crank signal; and means responsive to said engine temperature indicating signal for producing a fast idle signal when the temperature of said engine is less than a predetermined number of degrees.